1) Field of the Invention
The present invention relates to a method and a device each for controlling a cell transfer in an asynchronous transfer mode (ATM) device that handles fixed-length cells each including logical channel information and data information.
2) Description of the Related Art
Generally, in order to allocate network resources to each communication by means of statistical multiplexing, ATM equipment needs a cell transmission limiting capability to prevent congestion due to excessive uses of allocated network resources as well as overflow due to cell inflow to a receiving terminal at speeds over a processing speed, caused by cells disorderly transferred from a terminal and a variation in delay in a network.
For example, as such an ATM transfer control method, a time-sharing method where the virtual channel (VC) or virtual path (VP) sent by each time slot is predetermined as well as a method which uses the shortest transfer interval being integer times one cell processing time of a device have been considered.
However, the former has a disadvantage in that the statistical multiplexing effect cannot be obtained because the capacity is completely separated every VP or VC. The latter has a disadvantage in that a fine control cannot be established because the controllable transfer speed is a fraction of an integer of the device processing speed or the range control becomes complicated because of the uneven division of the variable transmission speed.